Overview
Custom Game Starts were introduced in the 4.10 update and allow for greater flexibility in getting into X4. Custom game starts can be broken down into two types: Budgeted and Creative Custom gamestarts with the former allowing players to create a start with a few restrictions and will not incur a modified tag. The latter is, as its name implies, far more creative and unrestricted but will incur a modified tag (preventing online functionality).
Budgeted Custom Game Starts
Creative Custom Game Starts